Muscle Pain & Fatigue When Taking Magnesium

Lynne Sheldon

A man holding his low back in pain.
(Image: Gajus/iStock/Getty Images)

Your muscles need magnesium to work properly, as do all your other organs. If you do not get enough of this mineral, you may experience muscle spasms and fatigue. While too much magnesium can be dangerous as well, muscle pain and fatigue are not common side effects of this. Talk to your doctor about your magnesium intake to determine the right dosage for you.

Magnesium and Muscles

Your muscles need magnesium to contract and relax smoothly, and this helps prevent spasms and general feelings of muscle weakness. Magnesium also contributes to your body’s energy production and distribution, without which your muscles and other organs could not function as they should. Magnesium helps the body make protein, too, which is imperative for muscle development and repair.

Low Intake

If you experience muscle pain and fatigue while taking magnesium, it could be that you are not taking enough. The amount you will need in a day depends on your gender, as well as other factors, which your doctor can help you determine. According to the University of Maryland Medical Center, the recommended dietary allowance or RDA of magnesium for most healthy women is 280 to 300 mg, while it is 270 to 400 mg for men. If you take less than this, you may experience symptoms of a magnesium deficiency, which include anxiety, agitation, insomnia, stomach upset, low blood pressure, confusion and hyperventilation. You may also experience muscle weakness and twitching, and if the deficiency becomes severe, continuous muscle contractions.

High Intake

Though low intake of magnesium is dangerous, taking too much poses risks as well. Muscle pain and fatigue are not common side effects of high magnesium intake. Most likely, you will experience vomiting, nausea, low blood pressure, confusion and a slow pulse. Should your toxicity become severe, you may lapse into a coma or even die. Too much magnesium can also lead to an imbalance of other minerals, and if your calcium levels are low, this can cause a calcium deficiency as well.

Additional Considerations

Never begin taking magnesium or any other mineral supplements without first discussing them with your doctor. People with certain medical conditions may need more magnesium than those who are healthy, and not meeting these needs can lead to muscle weakness and other symptoms of a magnesium deficiency. Talk to your doctor about the intake of magnesium that is best for you, and tell him if you are experiencing muscle pain and fatigue. It may be that the cause of your symptoms is something other than your magnesium intake.